| Background Obstructive sleep apnea (OSA) is a high incidence of sleep apnea, and its pathophysiological mechanism is complex. As a key non-anatomical mechanism of OSA, the arousal threshold(ArTH) is closely related to the severity and clinical manifestations of the disease. At present, the research conclusions about the influencing factors of ArTH are still controversial, and its characteristics and differences among people with different genetic backgrounds are still the weak link in the current research. Objective To explore the distribution characteristics of ArTH in patients with OSA and its differences in different populations, and analyze the key factors affecting ArTH, so as to provide evidence-based basis for the study of pathological mechanism of OSA and the formulation of targeted treatment strategies. Methods A retrospective analysis was conducted on 285 patients diagnosed with OSA according to the Multidisciplinary Diagnosis and Treatment Guidelines for Adult Obstructive Sleep Apnea, who underwent overnight polysomnography (PSG) at the Sleep Medicine Center of Inner Mongolia Mental Health Center from December 2022 to May 2024. According to the study design, the patients were divided into two different genetic background subgroups (hereinafter referred to as "Group A" and "Group B"). Data collected included basic demographic information, clinical data, Epworth Sleepiness Scale (ESS) scores, and overnight PSG parameters. The apnea-hypopnea index, lowest pulse oxygen saturation, and proportion of hypopneic events were used as criteria to determine the ArTH in OSA patients. Differences in the above indicators were compared between the Han and Mongolian OSA groups. Binary logistic regression analysis was used to identify factors influencing ArTH in the overall OSA population, followed by ethnicity-stratified regression analysis to preliminarily explore ethnic differences in these influencing factors. Results Among the 285 OSA patients, no significant differences were observed between the two groups in the proportion of low ArTH, ESS scores, other general characteristics, PSG parameters, or the proportion of patients meeting the three criteria for low ArTH (apnea-hypopnea index <30 events/h, lowest oxygen saturation >82.5%, and proportion of hypopneic events >58.3%) (P>0.05). Binary logistic regression analysis revealed that female sex (OR=2.421, 95% CI: 1.070–5.478), BMI (OR=0.847, 95% CI: 0.770–0.932), N1 sleep duration (OR=0.974, 95% CI: 0.963–0.985), and hypertension (OR=0.348, 95% CI: 0.143–0.848) were independent influencing factors for low ArTH. Stratified analysis by ethnicity showed that in group A OSA patients, female sex, BMI, and shorter N1 sleep duration remained independent influencing factors for low ArTH (P<0.05), whereas in group B OSA patients, only shorter N1 sleep duration (OR=0.951, 95% CI: 0.911–0.993) was an independent influencing factor for low ArTH. Conclusion arousal thresholdmay have conservative characteristics in different populations, but the pathophysiological mechanism of OSA may have population heterogeneity. |